As Americans’ hunger for burgers and chicken continues to grow, restaurant operators are tweaking their menus to meet consumers’ demands for new meats and higher quality.

An increasing number of limited-service restaurants have added better and more “natural” meat to their repertoires. At the same time, they are featuring other proteins.

From the growth of Angus menu items to the specialty burger craze, there has been no slowdown in sales of beef on a bun, according to a Technomic study last summer.

The Chicago-based market-research and consulting firm found that nearly half of consumers eat a burger at least once a week, up from 38 percent two years earlier.

While a good chunk of the boost was attributed to quick-serve value menus, there are other factors at work, says Sara Monnette, director of Technomic’s consumer research.

Diners “want to get something they really enjoy and that satisfies a craving,” she says. “For many people, that’s a burger and fries. Burgers offer great value paired with variety that matches what any one consumer can afford or is willing to spend.”

As fast-casual restaurants flourished by offering burgers with premium beef and other meats, quick serves responded “by offering both an affordable burger on the value menu and a more premium burger” that is bigger, uses more premium beef, and has a higher price, she says.

Of the many limited-service restaurants tracked by Technomic’s MenuMonitor, nearly two dozen use Angus beef in burgers or other menu items.

The company’s research also found that nearly 23 percent of consumers ages 18–34 find it important to have vegetarian burgers on the menu. There were also big gains in health-halo attributes such as using natural, hormone-free, and antibiotic-free meat.

NPD found that consumers expect to pay more to get food that is better for them, and “the older we get, the more dissatisfied we are in that,” Riggs says.

Another concern that operators have to overcome is the issue of taste. Many people believe that “good for you” food is intrinsically less flavorful.

Part of the problem dates to the 1980s, when restaurants tried to meet the low-fat craze. But many menu items simply didn’t taste good, and the food landscape soon was littered with failed concepts like D’Lites and KFC’s Fresher Cooker.

“If you are going to have these types of items on the menu, you have to be careful about positioning and price,” Riggs says. “And the food must taste good.”

One of the first concepts to succeed in that was Chipotle Mexican Grill, the Denver-based fast-casual pioneer founded by Steve Ells in 1993. It now has some 1,100 units in 39 states, Canada, and England.

Known for its giant-sized burritos, Chipotle was a small chain in 1999 of about 50 units, when Ells, a Culinary Institute of America grad, began to rework his recipe for carnitas—braised pork—because they were not selling well.

After reading about problems with concentrated animal feeding operations compared to more humane and natural ways to raise pigs, such as at Niman Ranch’s Iowa farms, Ells decided to visit both types of farming operations.

He was “horrified” at what he saw at the factory farm, company spokesman Chris Arnold says, and was alternately impressed with the old-fashioned, less cramped, and antibiotic-free way Niman was operating. He determined natural meat also tasted better.

“He had an epiphany,” Arnold says. “To serve the best food, you have to find more sustainable, natural sources. How the animal is raised shows up in the taste of the food.”

Chipotle now vows to use naturally raised meat, organic produce, and hormone-free dairy. The company serves 100 million pounds of natural meat a year, including all of its pork, 85 percent of its beef, and 75 percent of its chicken.

Raising livestock naturally costs more, and when Chipotle made the switch, prices went up. Most entrées are now $6.25–$6.65, but “people are willing to spend more money to get food that is obviously better,” Arnold says.

U.S. Department of Agriculture guidelines say natural meat is from livestock raised without growth additives and most antibiotics, and is not fed animal byproducts. Chipotle takes that a step further by requiring natural living conditions.

Natural is not organic, however.

“Organic is a federally regulated claim, with enforcement under the USDA,” says Gwendolyn Wyard, associate director for Organic Standards and Industry Outreach at the Vermont-based Organic Trade Association. “Standards are very strict.”

The biggest difference in the terms organic and natural is that organic livestock must have access to organic pastures free of pesticides and herbicides for at least three years. Animals also must get certified all-organic feed.

Early last year, Moe’s Southwest Grill switched its 420 restaurants to natural ingredients. The steak is from grass-fed and hormone-free imported beef, chicken is natural and cage-free, and the pork is hormone- and steroid-free.

“For an operation our size to commit to that is pretty amazing,” says the company’s executive chef, Dan Barash.

The change came with a small price hike among many franchisees, “but we felt this was the right thing to do,” he says. “We didn’t make a big deal about it. We just did it.”

Burritos range from $5.29 to $6.39.

Moe’s also offers tofu, the soybean-based alternative protein available at several other limited-service restaurants, including Noodles & Co. and Pei Wei Asian Diner. Much of the fast-casual tofu is organic.

Freebirds World Burrito has served grass-fed beef from Uruguay for a number of years. The 60-unit chain added natural pork in 2007 and switched to natural chicken a year later.

“Grass-fed beef is a little more expensive, but we think it is worthwhile,” says Steve Byrne, vice president of purchasing and culinary operations at Tavistock Restaurants, the Emeryville, California–based parent of Freebirds.

“More and more, people who are eating out want what’s good for them, what’s natural,” he says. “We decided we could help them make a choice by having great products.”

Grass-fed beef has a different flavor profile than meat from grain-fed animals. “You get more steak texture,” Byrne says. “It just has more flavor.”

The availability of grass-fed beef made a big difference for chef Shaun Doty when he opened Yeah! Burger in Atlanta.

“We were looking for great quality, and that dovetailed in finding great grass-fed beef at White Oak Pastures” in Bluffton, Georgia, he says. “I was looking for a local, sustainable provider, and buying from south Georgia hits the nail on the head.”

In addition to hamburgers, Yeah! has a sandwich that uses free-range chicken. His two-store operation also offers some alternative burgers, such as natural turkey, grass-fed bison, and veggie burgers with heirloom peas from South Carolina.

Basic burgers range from $5.99 to $7.99.

Doty has been able to ride a wave of success experienced by premium burger joints, many of which brought fine-dining food attributes to the limited-service world.

One of the first to use natural, upscale beef was The Counter. Since 2003, when founder Jeff Weinstein opened his first restaurant in Santa Monica, California, the enterprise has grown to nearly three-dozen units in 10 states and overseas.

He wanted the burgers to be better than the norm, so they are made with Red Angus beef from Meyer farms, known for environmentally friendly, humane, and free-grazing methods.

“We call it a ‘never never ranch,’ because there is never any hormones or antibiotics,” says Counter executive chef Marc Boussarie. “Red Angus is a superior breed, with more marbling and flavor, and the cattle are prairie-raised on grass and vegetables.”

The chicken and turkey for burgers at The Counter are also naturally raised. Meat-free burgers are made with 11 vegetables.

The Counter is known for build-your-own, one-third pound burgers, with dozens of different cheese, topping, and bun options starting at $8.75.

The chain also features a varying, monthly Market Selection protein choice that is chosen by local operators. Among the varieties have been bison, salmon, crab, carne asada, lamb, and ahi tuna. Bison and a fish protein, like salmon, may join the regular menu.

Even pizza is getting into the act. zpizza celebrated its 25th anniversary last year with a new pie using an all-natural, preservative-free pepperoni. The Irvine, California–based chain already has all-natural turkey among its toppings and wants to add natural ham.

“We start off with a great-tasting product, and our customers can feel better after eating it,” says Sid Fanarof, founder of the nearly 100-unit chain.

Turkey and chicken are perceived as healthier than red meat, so operators have generally found it easier to procure naturally raised poultry than beef.

Panera Bread shifted to antibiotic-free chicken in 2005.

“We couldn’t find the quality of taste and texture in the market at that time for all-white-meat chicken breast,” says Scott Davis, executive vice president and chief concept and innovation officer for the suburban St. Louis–based fast-casual leader with 1,500 units.

“We began working with some smaller farms, discovered the taste we wanted in an antibiotic-free chicken,” he says. It’s now in soups, salads, and sandwiches.

Panera tries to use antibiotic-free birds for its smoked turkey, but that has been harder to source. “There is a limited supply, but we are working through it,” Davis says.

Two of the biggest users of all-natural turkey are CKE Restaurants’ Carl’s Jr. and Hardee’s chains, which both introduced a trio of charbroiled turkey burgers in 2010.

Both chains have regular turkey burgers topped with produce and sauce on a bun, but they also sell two special turkey burgers. For Carl’s Jr., it’s guacamole and teriyaki turkey burgers, while Hardee’s has BBQ ranch and a mushroom and Swiss version.

“No one has introduced turkey like us,” says Brad Haley, chief marketing officer for the Carpinteria, California, company that has been a protein innovator. Hardee’s began offering Angus burgers in 2003, followed by Carl’s Jr. the next year.

Turkey burgers have been the chains’ third-best burger introduction.

“Our target group is young, hungry guys, but what we’ve seen is even with this group, there is more concern with where their food comes from and what’s in it,” Haley says.

Still, the quarter-pound turkey burgers—$3.29 for the base version and $3.49 for the special ones—“have to taste good or people won’t eat them.”

Turkey is also showing up in hot dogs at some restaurants and in breakfast meats at chains ranging from Dunkin’ Donuts to Einstein Bros.

A few brands have tried fish sandwiches. McDonald’s has had its Filet-O-Fish for decades and many others have fish promotions associated with Lent. Phillips Seafood Express sells a crab cake sandwich and a crab and shrimp wrap.

Some others offer veggie patties, albeit with limited success. Burger King has had one since the first quarter of 2002. The sandwich features a Morningstar Farms Garden Veggie Patty made of a variety of vegetables, grains, and spices.

A number of Subway restaurants offer a veggie patty under the name Veggie Max or Gardenburger. The Veggie Max has vegetables, egg whites, grains, and other items, while the Gardenburger has mushrooms, rice, onions, cheese, and more.

These two items account for a very small percentage of total sandwich sales.